Indicating instrument



0 9 5 9 9 5, l H m A L H C s H Sept. 14,192@

IIDICATING INSTRUIBIT 011111181 Filed June 18, 1917 2 Sheets-Sheet 1 Sept. .14 1926. 1,599,590

H. SCHLAICH INDICATING INSTRUMENT original' med June 1a, 1917 2 sheets-sheet 2 illatented Sept. 1 4, 192.6.

Hannan scnLAIcn, or LONG ISLAND crrY, Naw Yonx.

Appleman ma :une is, 1911, semaine. 115,244. Renewed my 1s, im.

This invention. relates to pressure or temperature indicatin instruments and is par ticularl applicabi to -air or other expansible ui thermometers but features of it may also be employed in connection with the conl struction of pressure gages for any purpose, particularly such as are utilizedrfor 'the inication of low pressures. Instruments embodying the invention by reason of their Afreedom from influence by vibration,l their lightness, sensitiveness, simplicity "and adjustability are particularly adaptable to usel for they measurement `of pressures or temperatures in connection withaer'oplanes, automobiles, motor boats, etc., asthe severe conditions'of such use do not affect their satisfacto operation'. For purposes of illus` tration have shown an instrument embodying the invention ap lied asa thermometer -for indicatingcylin er tempera-tures of an A internal `combustion engine of a'motor vehicle', in connection. with which I have also ut the 1nvention in .so far as it relates to the indicating instrument per se is not limited to this use nor to this'mode of application.

the thermo-element to the engine by inserting the same through a 'hole bored into the' cooling system. This construction,' while effective in securing a satisfactory thermal ,contact of the thermo-element therewith, isV

open to certain structural disadvantages due rincipally to the fact that the element is likely to bev-installed by garage lmen and others Whose skill in this type ofoperation is apt not to be high. It will be evident that unless the thermo-element is properly secured in the bore madeinto the coolingsystem, leaks are -verv liable to develop; and,

' moreover there exists the possibility of the A whatever reason, the thermometer bulb or other temperature responsive instrument is l' removed, 'allele4 isleft in the coolingr system which obviously must be stopped before they y p. I shownin Figure 6'.' vFigure ,11 isa detailed y -I vhave now observed that-in instances I element, 'as for example the thermometer bulb or tube; becominA detached in use, due to thefvibration of t eengine. Also the further diiiculty is presented that when, for

y engine can be operated y may obtain a satisfactory measure 'of .the

thermal condition of the engine by applying sponsive instrument to the exterior of a wall of the cooling system behind which is cooling liquid in the state of having been affected by the tem erature of the combustion chamber of a cy inder. In the form illustrated I ap ly a t armo-element to the jacket of the cy inder adjacent the combustion chamber, but obviously I may apply the thermo-element to any other part of the co'oling system wherein the cooling liquid lhas been affected by the heat of a combustion chamber or chambers and before it has been, cooled by the radiator. Thusv by virtue of my invention the above mentioned diiiiculties incidental to tapping thecooling system `are overcome in a simple and effective manner at the same time obtaining in a useful degree the thermal indication desired.

The present invention'may likewise be appliedto engines without water jackets or only partly )acketed by securing the thermoelement directly to the outside of the .cylinder vwall or other'heated portion of an outer motor Wall. In this manner an effective thermal connection of the temperature reis achieved. He-retofore it hasbeen proposed to apply vform a part of In the accompanying drawings which t is specification, Figure 1 is a diagrammatic view inside elevation showing a part of an internal combustion engine of a motor vehicle and showing one form of the instrument applied thereto in such a manner vas to indicate cylinder jacket temperatures. Figure .2 is `a face view of the indicating instrument. Figure 3 is a verticaly section through the instrument showing also the'thermo element' of the thermometer applied to the cylinder jacket wall. Figure 4' is a face view of amodified form of instrument. y.Figure .5 is a fragmentary' vertical section fof the instrument shown in Figure 4. ,Figures and 7 are a face view and section respectively of anothermodiied form ofjinstrument, Figure y8'is a detailed tive view of a dial of the form shown in Figures 4^ and 6. Figure 10 is` a detailed view of the hand -and vcompensating element perspective view ofv the compensating o r ating lever and associated parts employe inv the form of instrument shown in'Figures 2 and 3. Figure 12 is a perspective view of l0o` sectional view .on line VIII-VIII of Fig- .ure 7. Figgure 9 is agfra-gmentary perspecthe compensating element employed in the form of instrument shown in" Figures 4 and 5.

Referring in detail to the construction illustrated in Figures 1, 2 and 3 the inven-r tion is here shown as embodied in an air or gas thermometer applied to the indication of engine cylinder temperatures. The numeral 1 designates an internal combustion engine of a motor vehicle having cylinders 2 provided with water cooling jackets 3.. A temperature-responsive element in the form of a bulb containing an expansive fluid is applied to the engine in any suitable manner. As illustrated I have made use of a bulb attached to the outer surface of the cylindei` jacket wall. I preferably make the-bulb in the form of a flattened annulus 4 which has a central opening 5. The bulb is covered on the outside with asbestos or other heat in-` sulating covering 6, the bulb and covering being enclosed within a shell'or cap 7 preferably of metal. The shell, covering and bulb are firmly held in position by a screw 8 screwed into a threaded hole 9 bored partly through the jacket wall. The screw is tightened up so as to clamp the bulb in close contact with the jacket wall so that it takes its temperature from the latter. A tubel() of small or capillary bore and preferably flexible, leads from the bulb tol the instrument 11 which is securedin any suitable position, for instance upon the vehicle dash 12 where it may be readily observed by the driver while operating the vehicle.

In the construction illustrated the instrument is provided with a casing 13 having a ilange 14 adapted to engage the Vtront'of the dash, the body of the casing being externally threaded as indicated at 15, so that a collar.

or nut 16 may be screwed thereon for clamping the casing firmly in position. The Jfront ot the casing is arranged to be closed by a crystal 17seated upon a packing ring 18 and clamped in position by a bezel 19 attached to the casing by screws 20. Removably mounted within the casing is a frame or base plate 21 carrying the operative parts of the instrument. These parts include a pressure sensitive element, an indicating element and operative connections between the two. In the form ot instrument illustrated the pressure sensitive element comprises a box diaphragm 25 formed of two flexible corrugated discs 26 and 27 united at their outer edges. The disc 26 has a central opening 28 and is attached to a sleeve 29 which fits closely in the cylindrical opening 30 in a boss 31 formed on the frame 21, and capable of longitudinal and radial adjustment therein, suitable means -or securing the sleeve in adjusted position being provided such for instance as the set screws 32. On the disc 27 is a reinforcing plate 33 carrying an eccentrically located projection or 'of the diaphragm will permit.

43 which has attached to it a twist or helix 44. The end of this twist is supported in a bearing in the bottom of the trame 21. In the construction illustrated the bearing is formed by a screw 45, a cup shaped socket 46 in the end of xwhich receives the conically pointed end 47 of the twist (see Figure 11). At its outer end, the spindle 43 carries an indicating hand 50 which is normally7 urged towards a zero position by means of a hair spring 5l attached t0 thc spindle. Mounted on the frame or base plate opposite to the bracket 4Q are 'a pair of spaced arms or bracket members 52 each of which carries an adjustable conically pointed screw 53 and between the points of these two pivot screws is an arbor 54 upon which is mounted the operating lever 55 (see Figures 2, 3, and 11). The operating lever carries a member adapted to be engaged by the 'ulcrum 34 on the diaphragm and is formed at its ree end so as to operatively engage the twist 44. As

.illustratedthe lever has alixed to it in line with the axis ofthe diaphragm a boss 56 which is internally threaded and transversely lslotted at 57 and which carries an adjusting screw 58 to the lower end of which is attached an Aabutment disc 59, which normally rests lagainst the fulcrum 34. At its outer end the lever is provided with a slot 60 adapted lto receive the flattened helix or twist. Any increase in pressure in the box diaphragm 25 will result `in forcing outwardly the disc 27 thereby causing the fulcrum 34 to press upon the abutment 59 and swing the lever 55 about the pivot screws 53 thereby causing the slotted end of the lever to move along the twist. This will obviously result in causing the twist to rotate, thus moving the indicating hand. Upon a reduction of pressure in the box diaphragm the hair spring 51 will rotate the hand in the reverse direction, the contact of the twist with leverfas rapidly as the reduction in pressure As the spring 51 is constantly active the same edges of the twist will always. be in engagement with the same walls of the slot 60 so that there will be no lost motion'in operating the hand. For this reason it is not necessary that the slot 60 shall fit tightly upon the twist but ample play may be allowed to permit freedom of movement without binding.

In order to compensate for changes in temperature within the instrument itself which will of course atleet the expansion of the slotted end of the lever ieturning the the air or gas within the box diaphragm independently of the temperature of the bulb A4, the lever 55 is formed of superimposed strips of metal or 'other substance having different co-elicients o expansion; for nstance, the outer strip 65 may be of brass while the inner strip 66 is formed of nickel.

v- This construction, in ,accordance with the p changes.

well known action of such a bi-metallic strip, results inthe slight curvature of the lever in such a direction as to closely compensate for the changes in the expansion of the diaphragm due to local ltemperature In order vthat the position of the pointer may be readily observed and Acorrect readings obtained, a dial having a suitablescale thereon is preferably provided. As illustrated, the dial plate 67 issupported upon plate v41 and the ends of the bracket arms 52, this dial being provided with a scale 68. The screw 58 provides means for makv ingazero adjustment of the hand with relation to the scale. In -order that this adjustment may be readily made from time to time, if necessary, the dial plate preferably has an opening 69 through which'the head of the screw may be reached when the crystal 17 is removed and without otherwise disturbing the instrument. The initial adjustment of the instrument may also be accomplished by loosening the screws 32 and movmg the sleeve 29 and diaphragm in or out slightly as may be required. In many cases 'it is desirable to make an adjustment in the movement ratio existing between the diaphragm or other pressure-sensitive element and the movable indicating member. I am ,able to accomplish this result very simply by var ing the effective lengths of the arms of the eve'r 55. In the particular construction illustrated, this result is achieved by the partial rotation of the diaphragm' about the axis of the sleeve 29, which changes the position ofthe eccentric ulcrum 34, bringing it either nearer to or further from the,

pivot screws 53. In this way, it -will be seen that the fulcrum may be caused to engge with the'abutment disc 59 at any point tween the position most remote from the pivot screws53, as shown in Figure 3, and -the nearest position to the Ypivot screws,`

y 'which the -fulcrum will occupy when the `index hand moving furthest for a given diaphragm is rotated through 180. When the eccentric fulcrum` is 'in the position 'shown in Figure 3, the movements ofthe index hand will be a minimum as compared with the movements of the diaphragm, ythe displacement of the diaphragm when the fulcrum 34 is brought toa position nearest to the pivot screws 53.. This adjustment is very desirable as absolute uniformity in the i construction of the diaphragm is impossible and adjustment is necessary to secure a subvloop'shaped compensatingstrip 79.

stantial degree of uniformity in the' movements of the index hands ofdiferent instruments. This uniformity' between different instruments is desirable Vas keeping the movements of the hand within the permissible limits of range of the instrument and also in makingk possiblethe use of a scale having standard divisions thereon, which may be stamped out with a die or printed. If this substantial uniformity were not obtainable, each instrument would have to be separately calibrated for several points in its range and have its individual scale marked by hand. y In Figures 4, 5, 9 and 12 a modified con struction embodying features of the invention is shown. In'accordance with this construction a: helix or twist is mounted dii this construction I prefer to use two or more superimposed box diaphragme so as to obta1n an increased movement; as illustrated I- have shown connected with the box diaphragm 82 a second box diaphragm 83, the two eing'united by a central passage-84.-l

The effect is merely to double Ythe amount'oil movement obtained Vwith a single box dia-f bragui. As the diaphragm expands it will I e seen that the slots in the compensating strip will move alon the twist causing the same to rotate the ar or and move the index hand. -Local temperature changes which vary the pressure in the box diaphragm also act. upon the compensating strip so as to cause it'to bend, thus eithermoving its ends slightly outward away from the diaphragm or slightly in towards same, this movement compensating closely for the pressure variations due to local conditions. insurev correctl scale readings 'corresponding tothe various positions of the index hand` a hand marked dial laid oli to correspond with the successive, positions of the' hand mayv be employed, but for many purposes suchas for an engine temperature indicating instrument I preferl to use a dial construction provided with adjustable indicia, such for instance asthat illustrated in figures 4 and 9. In the construction shown the In `order toy dial plate 90 is provided with annulariy ary ranged slots 91. A number-of thin leaves 92 are secured to the underside of the dial in any suitable manner as by means of an eyelet 93 which is riveted over'so as to 'hold all ffthe leaves to the dial andiexert va suf- ,cient pressure thereon so that the leaves will be retained in adjusted position by friction( vEachlea is provided with suitable figures or .identifying indicia. Preferably also each leaf -is provided with abent over tongue 94 which engages the inner edge of the slot so as to hold the outer part of the leaf close to the underside of thedial where the numerals may be readily observed through the slot, the point of the tongue vposite the corresponding position .of the and. .So far as the several oints indicated by the leaves are concerne therefore the same accuracy is secured as with the hand marked dial and at very much less expense. An adjustment in the initial position of the diaphragm and compensating strip may be obtaine by rotating the screw threaded sleeve (see Figure') which will cause the diaphragm Ytobe moved further away from or nearer to the support 96 for the arbor carrying the twist. v v

. In Figures `6, 7, 8 and 10 I have shown another modification of my invention in which the compensation for local temperaturc variations is effected by mounting the hand loosely on the end of the arbor 101 and transmitting the movement from the arbor to the hand byV means of a bimetallic cmpensating strip 102. The latter I have shown in the form of a spiral the inner end oi which 103 is made fast to the arbor and the outer end 104 to the hand. Locai changes in temperature will cause the strip to coil or uncoil to a limited extent thus modifying the position of the hand with relation to its arbor. In the construction shown the arbor carries the twist 105 which works in a slot 106 in a piate 107 located over the chamber 108 set into a box diaphragm. The chamber is simply to give clearance for the portion of the twist projecting beyond the plate 1.07. Tne operation of the box diaphragm is the same as that previously described, the expansion oi' the diaphragm moving out the late 107 and thus causing the twistand index hand to be rotated. mln this instance I have shown the twist 105 as having a pitch decreasing from the end adjacent the diaphragm outwardly therefrom, the effect of which decrease is to cause the twist to rotate more quiflrly as the diaphragm expands. This results in giving the index h and a greater movement during the upper ranges of the scale which opens out this part of the scale and-makes readingof the same easier.' Obviously the variation in the pitch may be` ,I

arranged .so as to open any part of the scale.

. claim In an instrument for indicating the cylinder temperatures of an internal combustion engine, the arrangement ofthe twist as described so as to increase the degree of movement of the index hand through the up r `range of the scale is particularly desira le as the higher temperatures indicated by the instrument correspond to critical temperatures of the engine cylinders beyond which it usually is not safe to operate the engine for any length of time. Accordingly, the hand may be caused to have an extended and relatively rapid movement at or near the danger point, whereby it will Aact as a danger signal andclearly c all the attention of the operator to the fact that excessive temperatures have been reached` The variable pitch twist may be employed in like manner in connection with the other forms of instrument illustrated.'

AWhile I have shown and described in detail certain preferred embodiments of my invention asl illustrative of the best modes now known to be of practicing the same, it

is to be understood that I do not intend to limit myself to these specific embodiments but .intend to cover my invention broadly in whatever form its principle may be employed. i

Having thus described my invention, -I

1. In au instrument ofthe character described, thc combination of a pressure-sensitive actuating element, a bi-metallic compensating lever' arranged to be actuated by said element, a twist in operative en agement with a part of said bi-metallic ever and rotatable indicating means actuated by l said twist 2. In an instrument of the character described, the combination of a flexible diaphragm, a bi-metallic lever pivoted to a fixed support at one end and carrying means intermediate its ends bearing against said diaphragm, a twist o eratively engaged with the free end of said bi-metallic lever and rotatable indicating means carried by said twist.

3. In an instrument of the .character described, the combination of a flexible diaphragm, a bi-metallic compensating lever operatively engaged with said diaphragm and having a notched or bifurcated rtion, a flattened twisted member engaged y said bifurcated portion of the lever, fixed bear-5 ings in which said member is journaled and rotatable indicating means carried by said member.

4. In an instrumentof the character described, the' combination 'of indicating means, a twist, a `lever fulcrumed at one end and slotted at the other, said slotted end having o rative engagement of said twist, a flexibl); diaphragm mounted so-that it may -be rotated, a fulcrum mounted on said diaphragm eccentrick to 'the 'axis of rotation thereof, and means on said lever between the I ends therecf engaging saidv fulcrum.

tal forclosing the front of said casing, a

f 'irame mounted in said casing and comprisbi-metallic jing aback plate and forwardly projecting upper and lower brackets, a'dial4 plate carried by the outer ends of saidbracket, an arbor carried by the lower bracket, an index hand mounted on said arbor between said crystal an'd dial plate, a twist connected tp said arbor and extending rearwardly A4f roin the same adacent to said'lower bracket, a ever pivoted to said -upper bracket, extending across said .casing and having a slotted end engaging with said twist, an abutment carried by said lever between the ends thereof, an adjusting screw for ad'usting the position of` said abutment towar s or from the lever, a box dia lii'agni located substantially parallel-to said back plate and between the same and said lever,4

s'aid box diaphra m being mounted on a sleeve projecting t rough an opening in the back o said back plate, said sleeve and box diaphragm being capable of rotation vabout an axis normal to said back plate and a fulcrum eccentrically mounted on said diaphragm and adapted to 'engage' the abutment on said lever.

6. In an instrument of the character described, the combination of indicating means,

a box diaphragm, and operative connections betweenv the dia hragm and indicating means, said diap ragm being adjustably silipported-v whereby it may be moved so as to e ect an adj ustmentof the indicating means.

7.'In'an instrument of the character del scribed, the combination of indicating rection substantially means, a twist operatively connected therewith, aibox da hragm, operative connec- 8. In an instrument of the character de A scribed the combination of indicating means, :a box diaphragm, and operative connections between said diaphragm and indicating means, said dia hragm being adjustably l `silap supported vwhere it may be moved in an axial direction an Amay be' rotated about its axis, slid o rative connections including means for e ecting an initial adjustment of `the indicating meansfwhen said diaphragm is moved in an axial direction and for varythe movement ratio between the -diaand the indicating means when the gin is rotstedaboutite .corlit'iustion chamber of a Icy Afore it has been cooled bytheradiator,

temrature responsive element.

rature responsive :element for *d 'thei'uioineters,l comprising a atteued' annular bulb, and a clamping screw for securing vsaid bulb in contact with a surface of the engine, said screwfpassing through the cen- Itiattened fluid-filled bulb, means for securing said bulb with a flattened side in intimate thermal conductive contact with a heated portion of an outerv motor wall, said means comprising a metallic casinflr extending over the bulb and secured to the motor wall, and a layer of non-conducting material between said casingand lthe bulb, an indicating'instrument located in a position to be observed by the driver when operating the vehicle, and a liexible'tube connecting said instrument and bulb.

11. A-therinometer comprising a chamber having a heat-conducting wall vconstructed tov fit upon the outer surface of an object whose temperature is to be measured, means for holding said chamber with said wall in intimate Contact-with said object, a `heatinsiilating covering for the opposite wall of said chamber, said chamber containing an expansible duid, apressure controlled gage for indicating temperature, and a tube connecting said chamber with said gage.

12. A thermometer comprising a chamber having a heat-conducting wall constructed v opposite wallof said chamber, a s ell membei' surroundinv said heat-insulating covering, said cha-mber'containing'an expansible l fluid, a pressure controlled gage for indicating temperature, and a tube connecting said chamber with said gage.

, 13. A temperature responsive element for thermometers comprising a bulb tlaton one side andhaving an opening therethrough transverse'to said side, a casing for said bulb having an opening registering with that of the bulb, an insulating ing device passin through the openings -in the casing and bi1 b. 1.4. .A temperature indicating means for internal combustion motors of motor vehicles comprising a temperature responsive element, means for fixedly securing said element in intimate thermal conductive contact `with the exterior of a wall of the cooling system on the interior of which is cool: ing liquid affected by the tem erature of the inder a-nd bebeinlg exfiom Contact with the cooling qui lining between said casing and bulb, and an attach:

ist

said i lil by said wall, an indicating instrument located in a position tobe observed by thel driver when operating the vehicle and an operative connection between the temperature responsive element and the indicating instrument whereby the indicating instrument- Will be constantly affected by the temperature responsive element to give indication of varying thermal conditions of no1- mal operation of the engine as Well as indication of abnormal thermal conditions of said engine.

15. A thermometer comprising a chamber having a heat conducting wall constructed to fit upon the outer surface of an object whose temperature is to be measured, means Jfor iixedly securing said Wall of said chamber and said object in intimate contact vvith one another. a heat insulating covering for a Wall of said chamber` not in contact with the surface of said object, said chamber containing a temperature responsive element, an indicating Ainstrument located in a position to be observed by the driver when operating the vehicle and an operative connection between the temperature responsive element and the indicating instrument Wherebythe indicating instrument will be constantly aiected by the temperature responsive element to give indication of varying thermal conditions of normal operation of the engine together with indication of abnormal thermal conditions of said engine.

16. A thermometer comprising a chamber having a. heat conducting wall constructed to fit upon the outer surface of an object whose temperature is tobe measured, said chamber and object having mutually conforming surfaces over an extended contact area, means for fixedly securing said conforming surfaces firmly against one another, a heat insulating covering for a Wall ofsaid chamber, not in contact with the surface of said object, said chamber containing a temperature responsive element, an indicating instrument located in a position to be observed by the driver when operating the vehicle and an operative connection between the temperature responsive element and the indicating instrument whereby the indicat;

ing instrument will be constantly affected by the temperature responsive element to give indication of varying thermal conditions of normal operation of the engine together with indication of abnormal thermal conditions of Isaid engine.

HERMAN SCHLAICH; 

